Ruxolitinib is approved in both the EU and U.S. for the treatment of bone marrow disorder myelofibrosis, in which normal bone marrow is replaced by scar tissue. Abnormal bone marrow production causes strain and enlargement of the spleen, which tries to compensate for blood cell creation and results in various symptoms such as weight loss, extreme fatigue, bone or muscle pain, and decreased survival. The drug targets the underlying mechanism of myelofibrosis through its JAK 1 and 2 inhibition.

The Columbia University team repurposed the drug to treat alopecia areata, an autoimmune disease in which hair follicles are attacked and destroyed by the immune system. The scientists previously identified the immune cells responsible for attacking and destroying hair follicles in alopecia and used ruxolitinib to eliminate them. Three patients with moderate to severe alopecia were administered with a twice daily tablet for up to five months. All three showed restored hair growth which successfully obscured patches of hair loss.

“We’ve only begun testing the drug in patients, but if the drug continues to be successful and safe, it will have a dramatic positive impact on the lives of people with this disease,” said Dr. Raphael Clynes, who led the research, along with Dr. Angela M. Christiano, professor in the Departments of Dermatology and of Genetics and Development at CUMC.

Dr. Christiano, who suffered from the disease herself, said, “Patients with alopecia areata are suffering profoundly, and these findings mark a significant step forward for them. The team is fully committed to advancing new therapies for patients with a vast unmet need.”

The researchers’ work entitled “Alopecia Areata is Driven by Cytotoxic T Lymphocytes and is Reversed by JAK Inhibition” was published online in Nature Medicine.